Names

The definition of a penguin, according to
Encarta Encyclopediae :Penguin, common name for flightless, aquatic birds of the southern hemisphere.
The name penguin originally was applied to the now extinct great auk of the North Atlantic, a large flightless, black and white bird with an
upright stance.
Similar flightless birds were discovered subsequently in the southern hemisphere, and they were also called penguins,
a name that is now restricted exclusively to these birds.

The origin of the word penguin is not completely certain :

First possibility: from Welsh: "pen" = head and "gwyn" = white.

But there is a second possibility :
When you translate the Latin word "penguis" it means "fat or good fed".
The Romans probably gave the name for the auks and guillemots, which live in the Northern hemisphere and which have a fat-isolation layer.
These birds aren't a relative of the penguins, but were highly appreciated as food-supply by the seafarers.
When later on, Spanish and Portuguese explorers discovered similar looking birds in Africa and South-America, they probably
thought it was also a great auk and gave it the same name, in Spanish, penguino.
This could be very plausible too, considering the fact that fat (oil) was very important
as a supply for light and heat or to cook with.

The Latin name "Sphenisciformes"
(Order including all living and extinct penguins) comes from those penguins, first described in literature,
namely the African penguin (Spheniscus demersus), the South American magellanic penguin (Spheniscus magellanicus) and
the Humboldt penguins (Spheniscus humboldtii).
In the opinion of zoologists, these are the typical representative of penguins.
The word "Spheniscus" comes from Greek, meaning "wedge shaped", referring to
the form of wings and body of penguins.

In the order of Sphenisciformes, you only have one family classification : Sphenicidae.
This includes all penguin species, 17 living and all the extinct.

Many species are named after their discoverers.

The Humboldt penguin is named after the German natural scientist Alexander von Humboldt,
who visited South-America in 1799.

Ferdinand Magellan gave his name to the Magellannic penguin,
when, in 1519, he sailed around the world as the first European (and most likely as the first human).

Adélie penguins owe their name to a woman, who never set foot in Antarctica herself.
When a French expedition, under leadership of captain Dumont dÚrville in 1840 reached the ice frontier, they discovered an island and
named it after their captain. Later on land, they saw a little, fat penguin with a black coat and a white belly (like an apron),
they named it Adélie, after their captain's wife. Afterwards, a complete region of Antarctica (Adélieland) was named after her.

Emperor penguins owe their scientific name (Aptenodytes forsteri) to their discoverer, the first natural scientist
to reach Antarctica, the German Johann Reinhold Forster. Forster came to Antarctica in 1770, on Captain James Cook's ship, and
saved Cook's life during the voyage. Cook was weakened by hunger and cold. Forster served him fresh meat bouillon although
there was only rusk on board. But when Cook recovered, the ship's dog was missing. Maybe that's the reason why the emperors were named
for their appearance rather than their discoverer.

The name of the macaroni penguin comes from the Macaroni club, a group of English men in the 18th century,
who introduced the pasta macaroni in England and wore a yellow feather on their cap.

The gentoo penguin (Pygoscelis papua) got its name when they thought to be discovered in New Guinea in the 18th century.
Although it was a mistake, their name never changed.

At first descripted or mentioned:

The very first mention of penguins derives from historica in 1520, on the sailing trip around the world with Magellan.

In 1758 Linnaeus mentioned two species in his Systema Naturae: namely the african penguin (named 'Diomedea demersa') and
the rockhopper (named 'Eudyptes crestatus').

The king penguin is firstly described by Pennant in 1768.

Magellanic and gentoo penguin: mentioned by Sonnerat in 1776

In 1781, Reinhold Forster mentioned 9 species, including 4 new ones.

Meyen named the humboldt penguin in 1834.

The macaroni penguin is described by Brandt in 1837.

Hombron and Jacquinot added 2 more species in 1841: the adélie penguin and the
yellow-eyed.

In 1844 Gray described the fiordland penguin.

Also in 1844 the emperor penguin was described by Gray after an expedition with Sir James Clark Ross.

Schlegel published a monograph about penguins in 1876, which still applies today.

The galapagos penguin is mentioned by Sundevall in 1871.

Coves described 13 species in 1872.

In 1874 the white flippered little penguin was included and in 1876 Finsch mentioned
the royal penguin.

In 1953 the Snares crested penguin was described by Oliver.

Besides, there is a lot of confusion about the names in different languages.
In English the African penguin is also called "jackass penguin", translated in Dutch "ezelspinguin",
but this Dutch name refers to the English "Gentoo penguin". Both species have in common that they call like a jackass.
In Dutch they call penguins "pinguïns", in Spanish "pingüinos", in Polish "pingwine" and in South African
"pikkewyne", while the French "pingouin" goes back to the auks and guillemots and a penguin in French translates
to "manchot".

Here are the Latin scientific names for all 17 species and their modern names in four different languages.